Stenciling machine



July 20, 1954 Filed Dec. 22, 195C FII-5.1.1

G. J. KIRCHNER STENCILING MACHINE 4 Sheets-Sheet l July 20 l954 G. J. KIRCHNER STENCIL-ING MACHINE 4 Sheets-Sheet 2 Filed Dec. 2?., 1950 G. J. KIRCHNLR STENCILING MACHINE `Iuly 20, H954 Filed DeG. 22, 1950 @fw/fm?) @Amd/0% A@ July 20, 1954 G. J. KIRCHNER STEINCILING MACHINE Shee'ts-Sheet 4 Filed Dec. 22, 1950 Patented July 20, 1954 UNITED STATES PATENT OFFICE STENCILING MACHINE George J. Kirchner, Pittsburgh, Pa., assignor to United States Steel Corporation, a corporation of New Jersey 10 Claims.

1 This invention relates to improved machines for stenciling articles in a production line, such as pipe or the like during its manufacture.

An object of the invention is to provide improved stenciling machines which are readily interlocked with other equipment in a production line, such as a cut-off machine in a pipe mill, for automatically1 marking each article as it is delivered thereto.

A further object of the invention is to provide improved machines for stenciling articles in a production line, which machines include a stencil adapted tmoverlie each article as it arrives in the machine, a traveling spray gun, and means for automatically propelling the spray gun along the stencil after the arrival of each article and thus applying marking fluid thereto.

A further object of the invention is to provide improved stenciling machines which are fluid pressure operated and electrically controlled for automatically moving their stencil into a position overlying with each article as it arrives and then automatically moving their spray gun along the stencil and thus applying marking iluid thereto.

In accomplishing these and other objects of the invention, l have provided improved details of structure, preferred forms of which are shown in the accompanying drawings, in which:

Figures l and la taken together are a schematic view of a stenciling machine which embodies features of the present invention, and showing the duid pressure operating circuit and electric control circuit;

Figures 2 and 3 are respectively a top plan view and a side elevational View of the stenciling machine;

Figure 4 is an end elevational view from the direction indicated by the arrow 4 of Figure 3;

Figure 5 is a vertical sectional view taken substantially on line V-V of Figure 3; and

Figure 6 is a vertical sectional view of a modified construction of Stencil holder.

The drawings show the stenciling machine of the present invention in conjunction with a cutoff machine in a pipe mill. The articles which it marks are the cut lengths of pipe from this cut-off machine. However, it is apparent that similarly constructed stenciling machines could be used in conjunction with other production line equipment and for marking other articles.

Therefore the specific environmental structure and the specific articles are to be considered as exemplary only and in no sense limiting.

As shown schematically in Figure l, the cutoi machine includes outlet conveyor rolls I0, ro-

tatable cutter wheels I2, inlet and outlet chucks I t and I t respectively and a vertically movable pipe stop I5. The outlet chucks have an operating cylinder i5 and piston Il and the inlet chucks and pipe stop have appropriate operating mechanism not shown. A pipe P traveling in the production line enters the machine from the left as viewed in Figure l and passes over conveyor rolls I0. While the pipe is traveling, both chucks are opened and the stop i5 is lowered. When the pipe engages this stop, its movement ceases, the chucks are closed to clamp it in position, and the cutter wheels commence to sever a measured length therefrom. After j severance is completed, the stop is raised and the cut length moves out of the machine and the operations just described are repeated. The cutofl machine can be of any standard or desired construction and therefore is not shown nor dea scribed in detail. As hereinafter fully explained,

the stenciling machine of the present invention marks each measured length of pipe during the cessation of its travel in the line while it is resting on the outlet conveyor rolls and while the cutter wheels are severing this length.

The stenciling machine comprises a fixed framework which can be mounted on any suitable supporting structure, such as the frame which carries conveyor rolls I0, As shown in Figures 2, 3, i and 5, said fixed framework includes a longitudinal beam IS, the upper face of which carries a longitudinal rail I9, which in turn Carries a pair of upstanding twin-legged brackets 2! and 2l. Said brackets carry downwardly depending plates 22 and 23, which are bolted thereto so that they can be adjusted vertically (Figure 3) Plates 22 and 23 have lugs 24 extending back toward beam I8 and stops 25 extending inwardly toward each other. The framework also includes a guide rod 26- which extends the length thereof between the upper forward portions of brackets 20 and 2|. However, it is apparent that the exact construction of the framework could be varied without departing from the invention.

A stencil holder 2l is hinged with respect to the brackets on lugs 24 and has vertically adjustable legs 28 (Figure 3) which rest on stops 25 when the holder is lowered. The lowered position of the stencil holder is adjustable for the purpose of accommodating different diameters of pipe. In the construction illustrated this adjustment is accomplished by adjustment of the position of plates 22 and 23 on brackets 2E! and 2| and further by adjustment of legs 23, However, it is to be understood that this adjusting means is exemplary only and that other forms of adjusting means can be used. The stencil holder includes an open frame 29 of arcuate cross-section which carries a removable stencil 38. The latter ordinarily is made of heavy paper and slides into the holder. When the machine is adjusted properly, the stencil overlies the article with but slight clearance. The stencil can bear any markings it is desired to place on the article, such as a manufacturers trade mark.

Figure 6 shows a modified stencil holder in which the stencil frame 28a is hinged to the holder 2l on pins 29D. This arrangement facilitates insertion and removal of the stencil 38a.

The stencil holder 21 can be hinged freely to the in which event it merely yields to permit irregularities in the article to pass underneath. However, in the construction illustrated a cylin- Ei. and a piston 32 are connected between the stencil holder and bracket 2i. When the pipe is moving, the cylinder and piston lift the stencil holder sufficiently so that the stencil clears the pipe and any irregularities therein, and, when the pipe stops, they lower the stencil holder until legs 223 rest on stops 25. The control mechanism for effecting this motion is described hereinafter.

As best shown in the schematic View of Figure l, the machine comprises a piston rod 33 which is fixed at one end to bracket 2] and car ries a piston 34 at its other end. A movable fluid pressure cylinder 35 is mounted for reciprocable movement over said piston. Bracket 2l has a guide bushing 35 through which said cylinder inovably extends (Figure 2). This cylinder carries a pair of outwardly projecting plates 3l and 323 which are apertured for receiving guide rod These plates have slots 39 within which a pneumatically actuated spray gun 40 is mounted for vertical adjustment (Figures 2, 3 and 4). The gun has an operating valve 4I and a supply line d2 for feeding marking fluid thereto (Figure l). The gun itself can be of any standard or desirable construction which sprays marking uid when an air stream is applied and hence is not shown in detail. The gun is spaced above the stencil and is adjusted to the proper spacing for the best spraying effect. After the arrival of each pipe length, the cylinder propels the gun forward and then returns it, while the gun sprays marking fluid on the stencil and the pipe beneath. The pneumatic circuit Figures l and la together show schematically both the fluid pressure circuit for operating cylinders and 35 and spray gun 48 and also the electric control circuit. The machine is illustratedI es pneumatically operated, although it is apparent that hydraulic operation would be equivalent in many respects. It would be possible also to move the spray gun electrically on a forward and reversing screw driven by an electric motor. Cylinder 5E, which operates the outlet chucks I 4, has air conduits 43 and 44 which respectively admit compressed air for closing and for opening the outlet chucks. The control means for thus ad mitting air to this cylinder is part of the cut-off machine and not of the present invention and therefore is not shown.

./iir conduits 43a and 44a connect conduits 43 and 44 with cylinder 3l, which raises and low ers the stencil holder. Thus when air is admitted to cylinder l5 via conduit 43 to lower piston I'l and clamp the outlet chucks on the pipe, air also is admitted to cylinder 3l via conduit 43erl to lower the stencil. When air is admitted to cylinder I6 via conduit 44 to release these chucks, air

4 also is admitted to cylinder 3| via conduit 44a to lift the stencil.

The stenciling machine is connected to a main source of iiuid pressure, in this instance an air supply line 45, which has a branch 45a extend ing to a double solenoid operated, four-way valve dii, and a branch 45h extending to another solenoid operated valve 41. Cylinder 35 is double acting and flexible air conduits 48 and 48 connect valve 46 with the right and left ends respectively of this cylinder. Valve 46 has forward and return operating solenoids 5l) and 5I. When solenoid 58 is energized, valve 46 admits air from line 45 to conduit 48 and relieves conduit 49. Therefore cylinder 35 and spray gun 45 travel to the right or forward When solenoid 5I is energized, the valve admits air from line 45 to conduit 48 and relieves conduit 48. Therefore the cylinder and gun move to the left or return Normally the valve occupies this latter position. Flexible air conduits 52 and 53 connect valve 4? with the operating valve 4I and the spray gun 4E' respectively. Valve 4l has an operating solenoid 54 which, when energized, operates this valve for admitting air to both valve 4I and gun 49.

The electric circuit The electric control circuit includes an actuating switch 55 on the pipe stop I5, an actuating switch 5'6 on the outlet chuck I4, a two-pole limit switch 51 at the left on bracket 20 and another two-pole limit switch 58 at the right on bracket 2l. Switches 55 and 58 are normally open, but close respectively when a pipe Pcontacts stop i5 and when outlet chucks I4 close on the pipe. Limit switch 5l has two sets of contacts 's'a and 57h, the first of which are normally open and the second of which are normally closed. However, cylinder 35 in its retracted position holds contact 51a closed and contacts 51h open. Limit switch 58 has two sets of contacts 58a and 5317, the rst of which are normally closed and the second of which are normally open. Cylinder 35 in its extended position, after traveling forward,

opens contacts 5ta and closes contacts 58o.

The circuit includes a control relay CR, a tine delay relay T, a forward relay FWD, a return relay RET and a spray relay SP. Relay CR has one set of normally open contacts 59. Relay T has one set of normally closed contacts 653. Relay FWD has four sets of normally open contacts E I, 62, 63 and 64 and one set of normally closed contacts 85. Relay RET has two sets of normally closed contacts B6 and 61 and four sets of normally open contacts 68, '69, 'l0 and 1I. Relay SP has three sets of normally open contacts T2, I3 and '14.

The circuit has power lines I5 and 'I8 connected to any suitable outside power source. A conduce tor 'I connects line 'I5 with one side of switch 55. A conductor 'I8 connects the other side of switch 5t with one end of the coil of time delay relay T and with one contact of the normally closed set (58 of this relay. A conductor 19 connects the other end of the coil of relay T with line 16. A conductor connects the other Contact of set t0 with one end of the coil of control relay CR. A conductor 8l connects the other end of said coil. with line T6. Therefore, when the outlet chucks are lowered on the pipe and close switch 56, time delay relay T and control relay CR both are eri-- ergized. The current paths are from line l5 via conductor 11, switch 56, conductor I8, the coil of relay T and conductor 19 to line 'I5 and via contacts 60, conductor 80, the coil of relay CR y and conductor 8l to line 16. Thereupon the time delay relay commences timing and the control relay closes its normally open contacts 59.

A conductor 82 connects conductor 'Il with one contact of the normally open set 57a (now closed) of switch 5l. A conductor 83 connects the other contact of set ela with one contact of the normally open set 59 of control relay CR. A conductor 8e connects the other contact of set 59 with one side of switch in pipe stop I 5. A conductor 85 connects the other side of switch 55 with one contact of the normally closed set 58a (now closed) of switch 58. A conductor 86 connects the other contact of set 58o: with one contact of the normally closed set 56 of return relay RET. A conductor 8l connects the other contact of set t6 with one end of the coil of forward relay FWD. A conductor 8@ connects the other end of said coil with line lli. When the end of the pipe contacts pipe stop l 5, it closes switch 55 and conditions the current path to said coil, and, when contacts 5s of control relay CR close, they complete this current path and energize said coil. The current path is from line 'l5 via conductors 'il and 82, contacts conductor 83, contacts 59, conductor 8f3, switch 55, conductor S5, contacts 58a, conductor te, contacts conductor 8i, the coil of the forward relay and conductor 33, to line lS. Thereupon the normally open contacts il, 62, 63 and 6-'4 of the forward relay close and the normally closed contacts t5 open.

A conductor SQ connects conductor l' with one Contact of the normally open set 'iii of forward relay FWD. A conductor B connects the other contact of set Gi with conductor 85. Closing of contacts Si thus seals in the forward relay around switch l. The current path is from line l5, via conductors Ti and 39, contacts El, conductors SE and 85, contacts 58a, conductor 8S, contacts 65, conductor 8l, the forward relay coil, and conductor B to line lis?.

A conductor Si connects line 'i5 with one contact of the normally open set 62 of forward relay FWD. A conductor S2 connects the other Contact of set with one end of the forward operating solenoid 5o of valve 4t. the other end of this solenoid with one contact of the norinally open set B3 of the forward relay. A conductor et connects the other contact of set 63 with line Therefore closing of contacts S2 'and E3 energices the forward operating solenoid. The

current path is from line "i5 via conductor 9 I, contacts conductor $52, the solenoid, conductor S3, contacts t3 and conductor B, to line lli. Thereupon valve All admits compressed air from the main supply line te and branch 3511 to conduit 45.* 5

and the right end of cylinder 35 and at the same time relieves conduit le and the left end of cylinder 35. Cylinder 35 and spray gun 4t commence moving to the right.

A conductor 95 connects conductor Tl with one contact of the normally closed set Sib (now open) of liinit switch 5l. A conductor 96 connects the other Contact of set cib with one contact of the normally open set Sil of forward relay FWD. A conductor t? connects the other contact of set t4 with one end of the coil of spray relay EP. A conductor 9S connects the other end of this coil "with line it. Closing of contacts Eli of the forward relay conditions the current path to the spray recoil. As cylinder 5 moves away from limit switch 5l, this switch returns to its normal position; that its contacts 51a open and its contacts all; close. Closing of the latter completes the current path to the spray relay coil and energizes this relay. The current path is from line l5, Via

A conductor 93 connects conductors 11 and 95, contacts 51h, conductor 95, contacts 64, conductor 91, the spray relay coil, and conductor 98, to line 16. Thereupon contacts l2, i3 and i4 all close.

A conductor 99 connects conductor 86 with one contact of the normally open set 'I2 of the spray relay. A conductor I connects the other contact of set 'i2 with one contact of the normally closed set 6l of return relay RET. A conductor lill connects the other contact of set 6l with conductor el. Closing of contacts 'l2 seals in the spray relay around the forward relay. The current path is from line 'F5 via conductors Ti and t5, contacts ib, conductors 9S and 99, contacts l2, conductor |06, contacts El, conductors Illi and 9i, the spray relay coil and conductor S8 to line l5.

A conductor H32 connects conductor 'Il with one contact of the normally open set 73 of the spray relay. A conductor w3 connects the other contact of set 'I3 with one end of the operating solenoid 5A for valve 4l. A conductor IM connects the other end of this solenoid with one contact of the normally open set 'iii of the spray relay. A conductor Gil connects the other contact of set "it with line 1S. Closing of contacts 13 and le thus energizes solenoid 513. The current path is from line l5 via conductors 'H and |02, contacts 73, conductor 1&3, the solenoid, conductor lil-'1, contacts 'ifi and conductor m5, to line 76. Solenoid 54 operates valve 4l to admit air from the main supply line and branch ib to conduits 52 and 53 and to the spray gun il and its valve fi i, whereupon the spray gun, now traveling to the right, sprays marking fluid on the stencil.

At this point in the operation, switches 55 and 5S are closed, contacts 51a of limit switch 5l are open and contacts 51h closed, control relay CR is energized, time delay relay T is energized and timing, and forward relay FWD and spray relay SP both are energized and sealed in` Return relay RET and limit switch 58 have not yet acted and are in their normal positions shown in Figures la and 1 respectively. Solenoid 5l) of valve 45 and solenoid 5d of valve lll both are energized. Solenoid 5l of valve 46 has not yet acted and is cle-energized.

When cylinder 35 has moved fully to the right, it engages limit switch 53 and opens its contacts elle and closes its contacts 5to. Opening the former contacts breaks the current path to the forward relay FWD and thus de-energizes this relay, whereupon its contacts return to their normal positions. Opening of contacts 62 and 53 of said relay breaks the current path to the forward operating: solenoid 5t of valve (it. However. opening of contacts 64 of said relay does not creati the current path to spray relay SP since this relay is sealed in.

Conductor 3S hereinbefore referred to, is also connected to one contact of set 58o of lirnit switch 5t. A conductor |06 connects the other contact of set 5819 with one contact of the normally closed set 65 of forward relay FWD. A conductor it? connects the other contact of set 55 with one end of the coil of return relay RET. A conductor ist connects the other end of said coil with line it. Closing of both contacts 58o and contacts (when forward relay FWD is de-encrgized) cornpletes a current path through the coil of the return relay and thus energizes this latter relay. The current path is from line 15, via conductors il and 95, contacts 5in, conductor 555, contacts 58D, conductor IUE, contacts E5, conductor itl, the return relay coil, and conductor 03, to line T6. Thereupon the normally closed contacts of said relay open and the normally open contacts close.

A conductor |09 connects conductor |06 with one contact of the normally open set 68 of return relay RET. A conductor connects the other contact of set 68 with conductor 69. Closing of contacts 68 seals in the return relay. The current path is from line 15 via conductors 11 and 95, contacts 51h, conductors 9B, 99 and lH, contacts 66, conductors |09 and |05, contacts 65, conductor |01, the return relay coil, and conductor |08, to line 16.

A conductor I connects line 15 with one contact of the normally open set 65 of return relay RET. A conductor ||2 connects the other contact of set 69 with one end of the return operating solenoid of valve 46. A conductor H3 connects the other end of this coil with one contact of the normally open set 1G of said return relayA A conductor ||4 connects the other contact of set 16 with line 16. Closing of contacts 69 and 1G thus energizes solenoid 5|. The current path is from line 15, via conductor Hi, contacts 69, conductor H2, the solenoid, conductor H3, contacts 16, and conductor ||4, to line 16. Thereupon valve 46 admits compressed air from the main supply line 45 and branch 15d to conduit 59' and the left end of cylinder 35 and at the same time relieves conduit 43 and the right end of the cylinder. Cylinder 35 and spray gun commence moving to the left.

A conduct-or l5 connects conductor 9B with one contact of the normally open set 1| of return relay RET. A conductor HS connects the other Contact of set 1| with conductor 31. Opening of contacts 61 would break the current path to the coil of spray relay SP, except the spring adjustments of contacts 61 and 1i are such that contacts 1| close momentarily before contacts 61 open. Closing of contacts 1| completes a new current path to this coil and thus keeps this relay energized without interruption. The new current path is from line via conductors 11 and 95, contacts 51h, conductors 96, 99 and H5, contacts 1|, conductors ||6 and 91, the coil of the spray relay, and conductor 98, to line 16. Thus the spray gun 40 continues to spray marking fluid on the return movement of cylinder 35 in the same fashion as on its forward movement.

As cylinder 35 moves to the left, limit switch 5S returns to its normal position, resetting itself for the next cycle. Ultimately cylinder 35 reengages limit switch 51 and opens its contacts 51h and closes its contacts 51a. Opening the former breaks the current path to the return relay RET and returns its contacts to their normal position, whereupon solenoid 5| and spray relay SP are de-energized. The contacts of the latter relay return to their normal position, whereupon solenoid 54 is de-energized. This solenoid has a spring return which closes valve d1 and thus the spray from gun 46 ceases. Closing of contacts 51a resets the circuit for the next cycle.

In the meantime timer relay T times out and its contacts 60 open. This timer relay can be set to time out at any point after the forward relay FWD seals in, but before cylinder 35 reengages limit switch 51. Opening of its contacts 60 breaks the curernt path to the control relay CR and thus prevents the operating cycle just described from repeating itself on the same pipe length. When the outlet chucks |4 subsequently are lifited after completion of the cutting operation, switch 56 opens. Thereupon the time delay relay is de-energized and its contacts 6D close for the start of the next cycle.

Preferably a manual operating switch ||1 is connected across conductors 83 and 36 via a con ductor ||8 connected to conductor 83 and a conductor ||9 connected to conductor Sil. Closing switch ||1 energizes the forward relay FWD, provided cylinder 35 is retracted and engaging limit switch 51. The current path is from line 15, via conductors 11 and 82, contacts 51a, conductors 83 and H8, switch |1, conductors H9, and 85, contacts 58a, conductor 35, contacts 66, conductor 81, the coil of the forward relay and conductor 88, to line 16. The circuit then op" erates in the same fashion as before to propel the spray gun 40 along its path and back and to cause the gun to spray.

Operation Summarizing the operation, a pipe P moving from left to right on conveyor rolls l0 cf the cutoif machine contacts stop l5, whereupon chucks i3 and i4 are closed on the pipe and the cutter wheels I2 start making a cut. At the same time stencil holder 21 is lowered. Switches 55 56 close and energize control relay CR and time delay relay T. Energizing the former relay in turn energizes the forward relay FWD. which seals in, energizes the forward operating solenoid 56 of valve 46, and energizes spray relay SP. Erb ergizing solenoid 50 causes valve 46 to admit fiuid under pressure to the right end of cylinder 35 and to relieve the left end, thus propelling this cylinder and spray gun 40 to the right or forward across stencil 30. Energizing spray relay SP energizes solenoid 54 and causes valve 41 to operate spray gun 4D which sprays marking fluid on the stencil and the pipe underneath. When cylinder 35 moves away from limit switch it conditions the current path to the return relay RET and when the cylinder engages limit switch 58 it completes this current path and breaks the current path to the forward relay. The return relay is energized and seals in, energizes the return operating solenoid 5| of valve 46, and again energizes spray relay SP. Energizing sole-- noid 5| causes valve 46 to admit fiuid under pressure to the left end of cylinder and to relieve the right end, thus propelling this cylinder and the spray gun to the left or returning them. Spray gun 40 sprays marking fiuid as before.

It is seen that several obvious variations in the operation are possible. For example the spray gun could spray marking fluid on only one stroke of the cylinder 35, and this could be either the :forward stroke or the return stroke. Another possibility would be for the cylinder to make only one stroke for each pipe, that is a forward stroke for one pipe and a return stroke for the next.

In referring to the stencil as overlying the article, I do not necessarily mean that the stencil is above the article, but only that it is placed in proximity to the surface of the article anywhere around the periphery thereof.

The stenciling machine of the present invention furnishes an entirely automatic means for marking each article passing through a production line. It is readily interlocked with associated equipment in the line so that it marks each article as it arrives. At the same time it involves only simple mechanical structure, uid pressure operating mechanism and electric control mechanism.

While I have shown and described only cer- 9 tain preferred embodiments of the invention, it is apparent that modifications may arise. Therefore, I do not wish to be limited to the disclosure set forth but only by the scope of the appended claims.

I claim:

1. The combination with a pipe cut-off machine, of a stenciling machine comprising a stencil adapted to overlie a pipe which is supported by said cut-off machine, a spray gun spaced from said stencil and adapted to travel therealong and to spray marking fluid thereon, fluid pressure means for propelling and operating said spray gun, and electric control means actuated by each pipe as it comes to rest for cutting in said cut-off machine, said control means being connected to said fluid pressure means for operating the latter and thus marking each pipe as it is being cut.

2. The combination with a pipe cut-off machine, of a stenciling machine comprising a framework, a stencil device hinged to said framework and adapted to overlie a pipe which is supported by said cut-off machine and to move away from the pipe to allow irregularities therein to pass freely, a spray gun spaced from said stencil device and adapted to travel therealong and spray marking fiuid thereon, fluid pressure means for propelling and operating said spray gun, electric control means actuated by each pipe as it comes to rest for cutting in said cut-off machine, said control means being connected to said fluid pressure means for operating the latter and thus marking each pipe as it is being cut, and means interlocked with said cut-off machine for moving said stencil device into its overlying position when the pipe comes to rest for cutting and to its position away from the pipe while the latter is traveling.

3. The combination with a production line machine adapted to perform an operation on articles after they enter and come to rest therein, of a stenciling machine for simultaneously marking the articles comprising a framework, a stencil carried by said framework to overlie each article in the line as it comes to rest in said production line machine, a spray gun supported by said framework and spaced from said stencil to travel therealcng and to spray marking' fluid thereon, propulsion means supported by said framework for moving said spray gun, and control means actuated by each article as it comes to rest in said production line machine for operating said spray gun and said propulsion means.

4. A combination as defined in claim 3 in which said propulsion means includes a double-acting pneumatic cylinder and piston, and said control means includes a first valve connected to said cylinder and piston and an additional valve connected to said spray gun, and an electric circuit for operating said valves.

5. A combination as defined in claim 3 in which said stencil is hinged to said framework to move away from articles when they are traveling to allow irregularities in articles to pass the stencil.

6. A combination as defined in claim 5 including a mechanism for moving said stencil about its hinged connection on said framework, and additional control means for automatically operating said mechanism to move said stencil to its overlying position when the article comes to rest and to its position away from the article when the article is traveling.

7. The combination with a production line machine adapted to perform an operation on articles as they enter and come to rest therein, of a stenciling machine for simultaneously marking the articles comprising a framework, a stencil hinged to said framework to overlie each article in the line as it comes to rest in said production line machine and to move away therefrom when the article is traveling to allow irregularities in the article to pass, a double-acting fluid pressure cylinder and piston carried by framework above said stencil, a spray gun carried by said cylinder and piston to be propelled thereby along said stencil and to spray marking uid cn the latter, electrically operated valve means for controlling the admission of fluid under pressure to said cylinder and piston, additional valve means for operating said spray gun, and electrical control means actuated by each article as it comes to rest in said production line machine for operating both of said valve means and thereby spraying marking fluid along said stencil.

8. A combination as defined in claim 7 including a mechanism for moving said stencil about its hinged connection on said framework, and control means for automatically operating said mechanism to move said stencil to its overlying position when the article comes to rest and to its position away from the article when the article is traveling.

9. rihe combination with a production line machine adapted to perform an operation on articles as they come to rest therein, of a stenciling machine for` simultaneously marking the articles comprising a framework, a stencil supported on' said framework to overlie each article in the line as it comes to rest in said production line machine, a double-acting pneumatic cylinder and piston carried by said framework, a pneumatically actuated spray gun carried by said cylinder and piston to be propelled thereby along said stencil and to spray marking fluid on the latter, a solenoid operated valve for controlling the admission of air under pressure to said cylinder and piston, a second solenoid operated valve for controlling the admission of air to said spray gun, an electric circuit having relays for operating said valves for admitting air under pressure to said cylinder and piston and to said spray gun and thus propelling said spray gun and spraying marking fluid therefrom, and limit switches mounted on said production line machine and connected in said circuit for actuation by each article as it comes to rest in said production line machine.

10.A combination as dened in claim 9 in which said stencil is hinged to said framework to move away from articles when they are traveling to allow irregularities in articles to pass the stencil and including a mechanism for moving said stencil about its hinged connection, and additional control means for automatically operating said mechanism to move said stencil to its overlying position when the article comes to rest and to its position away from the article when the article is traveling.

References Cited in the le of this patent UNITED STATES PATENTS Number Name Date 1,732,683 Hubl Oct. 22, 1929 1,929,703 McDonough Oct. 10, 1933 2,355,930 Thorne Aug. 15, 1944 2,383,947 Wensel et al. Sept. 4, 1945 

